I dunno, it was always tough for me to separate Depp from Depp, I always saw a bit of him in his roles unlike someone like Gary Oldman for instance. Maybe it has to do with his fame more than anything. I think that's it. But in the end Bale's variety and dedication does it for me. There's something far more sinister, brooding and subtle about his stuff compared to Depp. Also, I don't see Bale taking any 'willie wonka' 'pirates of the caribbean' type of roles in the near future, both of which I'm not particularly a fan of.
As far as public personalities go, Depps got more bohemian cred but Bales got his outsider/loner thing going on. I like a mix of both, but I pick Bale's passive aggressiveness over Depp's here.